There are many methods known in the art for stabilizing bones, or for connecting portions of bones or different bones. Many of these methods use screws inserted into the bone structure and connecting elements held by these screws. It is also known in the art to use arcuate elements to fixate bones or to connect separate bones or bone parts. Such arcuate elements have a number of advantages over conventional methods of orthopedic fixing, using screws tapped into the parts to be fixed. One of the most important advantages is that the arcuate element, by virtue of its shape, provides positive resistance to linear pull out without the need to rely on the gripping strength of screw threads.
There are a number of prior art publications which describe the orthopedic uses of arcuate elements for connecting adjacent bones or bone parts together. Among these publications U.S. Pat. Nos. 6,607,530 and 6,923,811 to A. Carl et al., show arcuate elements for connecting adjacent vertebrae. According to one method described therein, the arcuate elements are held in place by virtue of their curved shape, being made as a press fit into the prepared arcuate aperture, or by virtue of the addition of a compressible material or bone growth materials, to ensure that the element is firmly wedged into its channel, or by the use of externally applied screws to fix the arcuate elements into the arcuate aperture.
In US Patent Application Publication No. 2005/0267481, also to A. Carl et al., there is shown an arcuate element for connecting adjacent vertebrae, which is secured to the vertebral bodies using interlocking screws that traverse the rod and penetrate the vertebra at angles that avoid sensitive neurological structures. However, this arrangement requires the drilling of additional holes into the vertebrae for the interlocking screws, with the additional danger of penetrating sensitive neurological structures.
In U.S. Pat. No. 5,928,267 to P. Bonutti et al, there is described, inter alia, an arcuate channel cut into two parts of a fractured bone, with a suture running through the channel, such that tightening and bonding the suture draws the bone parts together.
In U.S. Pat. No. 4,790,303 to A. D. Steffee, there is shown a barbed arcuate fastener for driving into adjacent bone parts, for securing a bone graft between the bone parts. One embodiment shows a pair of such fasteners, driven into the bone portions in opposite directions, and with their protruding end portions connected by a tensioned wire, to assist in retaining the fasteners in position. Specifically, if one of the fasteners tends to move out of the bone portions in a direction, opposite to the direction in which it was driven, it would be resisted by the other fastener which would have to move in the same direction to that which it was driven and further into the bone portions. However, the wire appears to play no part in stabilizing the rigidity of the structure of the two fasters, since it is attached flexibly to their outer ends, and is only described as resisting their mutual withdrawal.
Each of the prior art inventions mentioned above has some aspect which may be disadvantageous in use. There therefore exists a need for a new apparatus and method for fixing or joining bone parts together, which is simple in application, provides a stable connection with the bone, and may provide either a rigid structure to the bone or bones themselves, or a sound connection to other parts such as dynamic stabilizers, and without undue danger to the subject during implementation.
The disclosures of each of the publications mentioned in this section and in other sections of the specification, are hereby incorporated by reference, each in its entirety.